Process for increasing the fastness to light of basic dyestuffs



Patented Nov. 26, 1 929 UNITED STATES PATENT IOFVFICE PAUL BABE, or LEVERKUSEN-ON-ITHE-RHINE, GERMANY, AssIeNoR. 'ro GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A. CORPORATION OF DELAWARE I PROCESS FOR II TGREASING- EHE FASTNES S T-LIGHT OF BASIO DYESTUFFS- No Drawing. Application filed September 20, 1927, Serial No. 220,830, and in Germany August 12, 1826.

In the copending application, Serial No. 190,129, filed May 9, 1927, there are described new molybdenum phosphotungstate compounds obtainable by reduction-of the two 5 complex molybdenum phosphotungstic acids of the general formula:

'n (W0 M00 .P O .3H O wherein n stands for one of the numbers 18 and 24 which compounds are soluble in water Very easily, are quite stable in air and arere convertible into molybdenum phosphotungstate acids by means of oz cidizing agents.

The complex molybdenum phosphotungstic acids may be preparedgin the following manner, all parts being by weight:-

100 parts of sodium tun state 25 parts of sodium moly date 24 (W0 +MoO .P O .3H O separates in large crystals. The addition of ammonium salts to the mother liquor causes no turbidity which means that the acid of the formula:

24(wog1 M0o,- .P o,. H,o is separated quantitatively. By the addition of about parts of ammonium chloride to the filtrate the acid of the formula 18 (W0 M00 .P O .3H O

is salted out. I

The reduction may be effected in the usual way, for instance in aqueous solution by means of sulfurous acid, bisulfite, hydrosulfite, the lower oxidation products of.

molybdenum, grape sugar or the like, and from the reduced solution the new products may be precipitated, for instance with hydrochloric acid.

) Now I have fdund that by subjecting ma-g terials dyed by means of basic dyestufl's to a 'ing without rinsing.

4. A process for increasing the fastness to light of dyeings with basic dyestuffs which subsequent treatment with these compounds, the fastness to light of the dyeings is considerably increased. For this purpose I prefer to treat the dyed materials with diluted aqueous solution of one of the above described reduction products.

The following example will illustrate my invention without limiting it thereto.

Example A 1% dyeing of rhodamine B-Extra (compare colour Index 1924, page 190, N0. 7749) on a tannin-antimony mordant is treated for "half an hour at a temperature of about 50-60 C. with a solution containing from 0.1 to 0.2

grams of the product obtainable by reduction of the molybdenum phosphotungstic acid of the formula in 100 cc. of water and dried without rinsing.

The dyeing isconsiderably more fast to light" than the untreated dyeing.

I claim: 1. A process for increasing the fastness to consists in treatin the dyeings with a compound obtainable y reduction of a'complex molybdenum phosphotungstic acid wherein n represents one of the numbers 18 and 24. 2. A process for increasing the fastness to light of dyeings with basic dyestufi's which consists in treating the dyeings with an aqueous solution of a compound obtainable by reduction of a complex molybdenum phosphotungstic acid wherein n represents one of the numbers 18 and 24.

3. A process for increasing the fastness to light of dyeings with basic dyestuffs which consists in treating the dyeings I with an aqueous solution of the compound obtainable by reduction of. a complex molybdenum 'phosphotungstic acid wherein n represents one of the numbers 18 and 24 and then dryconsists in treating the dyeings with an aqueous solutionv ofthe compound obtainable 75 light of dyeings with basic dyestuffs which by reduction of the complex molybdenum phosphotungstic acid of the formula 24(WO +MoO ).P 0 .3H O

6. Materials dyed by means of a basic dyestufi and treated subsequently with an aqueous solution of the compound obtainable by reduction of the molybdenum phosphotungstic acid of the formula 24(WO +MoO ).P 0 .3h O

In testimony whereof I have hereunto set my hand,

PAUL BABE.

Certificate of Correction Patent No 1 736 835 I Granted November 26, 1929, to

. PAUL BA E tion of the above It hereb certified that eiror appears 1n the prlnted spec fica numberb d pategit requiring correction as follows: Page l, (9, 8?, and 94, claims 1, 2, and 3, and page 2, line 9, claim 5, after the Word acid lnsert 0f the general fown-ula: n(WO +M00g).P O .3H 0

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case 1n the Patent Oflice.

Signed and sealed this 24th day of December, A. D. 1929.

[SEAL] M. J. MOORE, Acting flmmnissioner of Patents. 

